Multiple drilling machine



Oct. 10, 1933. c. L. MAHREN 4 4 1,9

' IULTIPLB DRILLING ucnxma Filed Oct. 17. 1932 2 Sheets-Sheet 1 lNvNTOKa mchh n Patented Oct. 10, 1933 MULTIPLE DRILLING MACHINE Carl LeonardMahrn, Hoganas, Sweden, assignor to A.B. Coma Multiple Drill MachineCo., Malmo, Sweden, a corporation of Sweden Application October 17, andin Sweden 3 Claims.

The present invention relates to a multiple drilling machine especiallyfor drilling brush heads and the like and having drills provided withscrew-shaped stems rotatable by means of a reciprocable plate which isin engagement with said stems.

The object of the invention is to provide a multiple drilling machinewhich is capable of drilling, in one single operation, a practicallyunlimited number of holes the axes of which are inclined towards eachother at any angle.

According to the present invention each drill stem is adapted to be fedin the direction of its own axis towards a fixedly positioned work piecesaid drill stems forming any angle with each other.

The invention is illustrated in the accompanying drawings, in which Fig.1 is a vertical cross sectional View of an embodiment of the machineaccording to the invention, and

Fig. 2 is a vertical longitudinal sectional view of said embodiment ofthe machine.

While the machine shown in the drawings is a vertical one, it should benoted that the invention is not limited to said type of machines and,generally, horizontal embodiments should be preferred for reasons statedbelow.

In the embodiment of the machine shown in the drawings, 1 is aframe-work, four vertical columns 2 being secured to the upper surfaceof said frame-work. At equal height above said upper surface of theframework, the columns are provided with offset portions 4 formingtransitions to the upper portions 3 of the columns, said upper portionshaving a smaller diameter than the lower portions of said columns 2. Onthe offset portions 4 a guide plate 5 is supported and clamped againstsaid offset portions by means of nuts 6 provided on a screw threadedportion of the columns.

' The guide plate 5 is provided with a plurality of perforations theaxes of which are parallel as viewed in the section according to Fig. 2but inclined towards each other as viewed in the sec tion according toFig. 1.

At th centre of one of the longitudinal sides of the frame-work 1 avertical rod '7 is positioned, a feed lever 8 being pivoted to the upperend of said rod 7. Above the guide plate 5 said lever 8 is provided witha horizontal hole, and upon a pivot 9 in said hole a feed breast 11 issupported by means of perforated lugs 10, said breast thus normallybeing positioned at a distanee above the guide plate 5. At each cornerthe feed breast 11 is provided with a vertical hole, and by means ofsaid holes it is guided upon the upper portions 3 of the columns 2. Inthe embodiment shown, both the guide plate 5 and the feed breast 11 arebent in the section according 1932, Serial No. 638,243, October 26, 1931to Fig. 1 the concave side facing downwards. However, this is not anecessaryfeature but said members may also be fiat or have any othersuitable shape.

A rectangular frame 12 has a hole in each of its corner portions saidfour holes forming guide members to the frame 12 upon the columns 2,said frame thus being reciprocable in a vertical direction on thecolumns whilemaintaining its horizontal position. To the frame 12 asubstantially rectangular plate 14 is secured, said plate being providedwith a plurality of slots 15 extending transversely to the frame 12. Theslots may also be formed by mounting bars transversely to the frame,said bars forming slots between them, or in other suitable ways.

At the middle of each of the shorter sides of the frame 12 said frame isprovided with a horizontal arm 12a carrying a horizontal crank arm 16, aconnecting rod 17 being rotatably mounted upon said crank arm 16. Eachof said connecting rods is rotatably mounted, at its opposite end, uponanother crank arm 18, said crank arm 18 being in turn eccentricallymounted upon a fly Wheel 19. i The fly wheels 19 are mounted uponopposite ends of a shaft 20 mounted longitudinally of the frame-work 1in bearings 22 provided in the short walls of the frame-work 1, andwithin said frame-work a belt pulley is secured to said shaft 20.

A plate 23 serving as a drill guide is connected to the upper surface ofthe frame-work 1 by means of screws 24 in such a manner as to form asuitable space between said upper surface and the lower surface of thedrill guide 23. Similarly to the guide plate 5, the drill guide 23 isprovided with perforations to the same number as those provided in saidguide plate 5, said perforations of the drill guide being parallel asviewed in the section according to Fig. 2 but inclined towards eachother in the section according to Fig; 1. Beneath the drill guide 23 adisc 25 of wood or other soft material is tenoned into the upper surfaceof the frame-work 1, the joint preferably being effected in such amanner as to make the disc 25 and adjacent portions of the upper surfaceform a flat surface.

In each perforation of the guide plate '5 a pin 26 is providedsurrounded by a screw spring 27 adapted to maintain the upper end 28 ofsaid pin 26, which is preferably rounded, in permanent contact with thefeed breast 11 reciprocable in a vertical direction above the guideplate 5.

To the lower end of each of the pins 26 projecting from the lower sideof the guide plate 5 a metal strip 29 twisted likea screw is connected,said metal strip extending through a slot 15 of the plate 14 and shapedas, or provided with, a drill 30 at its lower end, said drill preferablybeing in the form of an anger but provided with two edges. so as toenable it of boring in both directions of rotation. Each drill 30extends into one of the perforations of the drill guide 23, thework-piece 31 being positioned beneath said drill guide 23 and theposition of said work-piece being determined by adjustable guidingdevices, such as screws 32.

The operation of the machine is as follows:

A work-piece 31, such as a brush head'whichv is to be provided with anumber of perforations or bores not exceeding the number of perforationsof the guide plate 5 and the drill guide 23, is positioned upon the disc25 the under side of said brush head facing upwards. Here the feed lever8 ought to be in raised position so as to allow the feed breast 11 topermit the springs 27 to keep the drills raised to such an extent as toenable the Work-piece, 31 to he introduced beheath the lower ends of thedrills. On the other hand a stop or the like should be provided limitingthe upwards movement of the feed breast 11 in order to prevent the pins26 and the drills 30 from being pulled out of their perforations in theguide plate 5 and the drill guide 23 respectively.

By a belt passing around the belt pulley 21, driving power istransmitted from a source of power of any kind, such as an electricmotor, to the shaft 20, said shaft together with the fly wheels 19 thusbeing rotated in one direction or the other. Hereby the connecting rods17 will cause the frame 12 guided upon the columns 2 to reciprocate in avertical direction, and since the slots 15 of the plate 14 are onlyslightly wider than the smallest, dimension of the strips 29 each strip,29 together with its drill 30 is caused to rotate in one direction whenthe frame 12 is moving upwards and in the other direction when saidframe 12 is moving downwards. The speed of rotation is dependent partlyupon the speed of reciprocation of the frame 12 and partly upon thepitch of the screw line of the strips 29.

By a suitable pressure exerted upon the feed lever 8 in a downwardsdirection the drills are forced into the work-piece 31 to the extentdesired the drills hereby cutting in both directions of rotation. If theperforations extend all through the work-piece the soft disc 25 preventsthe drills from being broken when their extreme ends project beyond thework-piece.

When the boring operation is finished the feed lever B is raisedthedrills 30 then being extracted from the bored holes by the action of thesprings 27 and again raised into their upper position. The work-piece 31is removed-from the machine and then another work-piece may beintroduced into the machine and bored.

It is evident that every desirable direction and position of theperforations of the work-piece may be obtained within very wide limitsby changing the guide plate 5, the drill guide 23, the plate 14, and, ifnecessary, the feed breast 11. It is not necessary, of course, that thedrills are parallel in the section according to Fig. 2 but, if desired,they may be inclined towards each other also in said section the onlyprovisions being that the slots 15 of the plate 14 be directed in amanner allowing the reciprocation of the plate 14 without breaking thestrips or spindles 29 and that the bending of the feed breast 11 besuitable for the purpose. Thus also perforations or bores which areinclined towards each other in the section according to Fig. 2, such asthe perforations at the ends of several types of brushes, may beboredsimultaneously with the other perforations. Generally, it is evidentthat an unlimited number of variations of the position, direction andnumber of the perforations or bores may be cfiected only by changing theparts mentioned above, or some of said parts, and by performingcorresponding alterations of the number and position or the drills.

In the case of horizontal machines the advantage is gained that boringsand the like accumulating upon the drill guide 23 in a vertical machinedrop to the ground. In this case, it may also be advantageous to designthe machine in such a manner as to make the under side of the work-piecevisible during working whereby it may easily be ascertained whether adrill has become broken or otherwise made useless. If so, the machine isstopped and then the useless drill is easily replaced.

In order to prevent losses of lubrication materials and to protectagainst splashes of such material the machine may be provided with aprotecting casing enclosing the machine above the frame-work and beingprovided with slots necessary for allowing the movements of projectingmovable parts, such as the arms 12a.

The design of the machine may be varied in various manners within thelimits of the invention, and accordingly the invention should not beconsidered to be limited to the embodiment shown in the drawings anddescribed above, said embodiment forming an example only.

What I claim and desire to secure by Letters Patent is:

1. In a multiple drilling machine, drills, spindles provided on saiddrills, said spindles being screw-shaped, inclined towards each otherand adapted to be fed longitudinally, and a plate provided with slotsengaging said spindles and adapted to be reciprocated in order to rotatesaid spindles.

2. In a multiple drilling machine, drills, spindles provided on saiddrills, said spindles being screw-shaped, inclined towards each otherand adapted to be fed longitudinally, pins provided on said spindles atthe end opposite to the drills, a guide plate stationarily positionedand provided with perforations, said pins being rotatably anddisplaceably mounted within said perforations, springs actuating saidpins in a direction outwards from said guide plate, and a plate providedwith slots engaging said spindles and adapted to be reciprocated inorder to rotate said spindles.

3. In a multiple drilling machine, drills, spindles provided on saiddrills, said spindles being screw-shaped, inclined towards each otherand adapted to be fed longitudinally, pins provided on said spindles atthe end opposite to the drills, a guide plate stationarily positionedand provided with perforations, said pins being rotatably anddisplaceably mounted within said perforations, springs actuating saidpins in a direction outwards from said guide plate, a feed breast, afeed lever connected to said feed breast, said feed breast being adaptedto be reciprocated by means of said feed lever in order to feed saidpins longitudinally against the action of said springs, and

a plate provided with slots engaging said spindles .i

and adapted to be reciprocated in order to rotate said spindles.

CARL LEONARD MAHREN.

